STATE HOUSE — Pivoting from the ongoing debate over whether the state should legalize marijuana for adult use, lawmakers on Tuesday were asked to grapple with a new question around the drug: are marijuana plants an agricultural crop or a controlled substance?

At issue is a Plympton farmer’s plan to build a marijuana cultivation center on his agricultural-residential property, also home to cranberry bogs and horse pastures. Jeff Randall, a fourth-generation farmer backed up by town counsel and two of the three members of the Plympton Board of Selectmen, contends the agricultural zoning gives him the right to grow marijuana without a special permit.

“We’re not asking to do sales,” Randall told the Joint Committee on Municipalities and Regional Government during a hearing Tuesday. “We’re only asking to do agriculture, which, you know, if you raise it from a plant that grows in the ground and photosynthesizes, it’s agriculture.”

Neighbors, the third selectman, and the legislators representing Plympton disagree, asserting that marijuana cultivation would not be allowed by right on the property.

“The law is very clear,” said Sharon Housley, one of the neighbors opposing Randall’s proposal. “Marijuana is not agriculture. It’s a controlled substance. It is not the same as corn on the cob or green beans.”

Their bill (H 4186) amends the state’s zoning law to spell out that the term “agriculture” does not “include the growing, cultivation, distribution or dispensation of marijuana,” which Calter said would clarify that marijuana growth is governed instead by controlled substances and medical marijuana laws.

“In order to resolve this community dispute and any other community dispute that could arise in any of our communities with a farm, all parties agreed the best way to resolve this is to codify the existing legislation through this bill,” Calter told the committee.

Massachusetts voters legalized medical marijuana by approving a ballot question in 2012, and there are now six dispensaries operating in the state. An initiative petition on track for this November’s ballot would ask voters to decide whether all adult use of marijuana should be legal and regulated in Massachusetts.

Randall asked the municipalities committee to carefully consider the zoning legislation and any potential consequences.

“I think that farmers should have the opportunity to grow a product that’s agricultural,” he said. “I don’t think we should leave it up to big pharma, because we know where that leads. At least if farmers who are able to do this, we can maintain our family farms in the future.”

Sen. Barbara L’Italien of Andover, who co-chairs the committee, told Randall that she intended to approach the zoning question as “a neutral broker” and that committee members would need to consult with the Department of Public Health and the attorney general’s office.

Committee member Rep. Carole Fiola called the issue a “tough one” as the marijuana industry expands and lawmakers continue to learn about the field.

“Obviously farmers, especially cranberry farmers, are struggling, and I understand that,” the Fall River Democrat said. “Even a piece of my district has cranberry farming in it and it surely is a challenge, so finding creative and innovative new ways to interpret agriculture is important.”